Blood pressure and leg deoxygenation are exaggerated during treadmill walking in patients with peripheral artery disease

• Published in: Journal of applied physiology (1985) Vol. 123; no. 5; pp. 1160 - 1165
• Main Authors: Miller, Amanda J., Luck, J. Carter, Kim, Danielle Jin-Kwang, Leuenberger, Urs A., Proctor, David N., Sinoway, Lawrence I., Muller, Matthew D.
• Format: Journal Article
• Language: English
• Published: United States American Physiological Society 01.11.2017
• Subjects: Aged; Ankle Brachial Index; Biomarkers - blood; Blood Pressure; Deoxygenation; Echocardiography; EKG; Electrocardiography; Exercise Test; Exercise Tolerance; Female; Fitness equipment; Gastrocnemius muscle; Heart Rate; Humans; I.R. radiation; Infrared spectra; Infrared spectroscopy; Leg; Legs; Lower Extremity; Male; Middle Aged; Muscle, Skeletal - blood supply; Muscle, Skeletal - metabolism; Muscles; Near infrared radiation; Oxygen; Oxygen - blood; Oxygen Consumption; Oxygen content; Patients; Peripheral Arterial Disease - blood; Peripheral Arterial Disease - diagnosis; Peripheral Arterial Disease - physiopathology; Skeletal muscle; Spectroscopy, Near-Infrared; Time Factors; Treadmills; Vascular diseases; Vein & artery diseases; Walking; blood pressure; near-infrared spectroscopy; peripheral artery disease; walking
• ISSN: 8750-7587; 1522-1601; 1522-1601
• DOI: 10.1152/japplphysiol.00431.2017

The purpose of this study was to investigate blood pressure (BP) and leg skeletal muscle oxygen saturation (Smo 2 ) during treadmill walking in patients with peripheral artery disease (PAD) and healthy subjects. Eight PAD patients (66 ± 8 yr, 1 woman) and eight healthy subjects (65 ± 7 yr, 1 woman) walked on a treadmill at 2 mph (0.89 m/s). The incline increased by 2% every 2 min, from 0 to 15% or until maximal discomfort. BP was measured every 2 min with an auscultatory cuff. Heart rate (HR) was recorded continuously with an ECG. Smo 2 in the gastrocnemius muscle was measured on each leg using near-infrared spectroscopy. The change in systolic BP from seated to peak walking time (PWT) was greater in PAD (healthy: 23 ± 9 vs. PAD: 44 ± 19 mmHg, P = 0.007). HR was greater in PAD patients compared with controls at PWT ( P = 0.011). The reduction in Smo 2 (PWT − seated) was greater in PAD (healthy: 15 ± 12 vs. PAD: 49 ± 5%, P < 0.001) in the most affected leg and in the least affected leg (healthy: 12 ± 11 vs. PAD: 32 ± 18%, P = 0.003). PAD patients have an exaggerated decline in leg Smo 2 during walking compared with healthy subjects, which may elicit the exaggerated rise in BP and HR during walking in PAD. NEW & NOTEWORTHY This is the first study to simultaneously measure skeletal muscle oxygen saturation and blood pressure (BP) during treadmill exercise in patients with peripheral arterial disease. We found that BP and leg deoxygenation responses to slow-paced, graded treadmill walking are greater in patients with peripheral arterial disease compared with healthy subjects. These data may help explain the high cardiovascular risk in patients with peripheral arterial disease.